platform/x86: dell-wmi-sysman: Don't hex dump plaintext password data

set_new_password() hex dumps the entire buffer, which contains plaintext
password data, including current and new passwords. Remove the hex dump
to avoid leaking credentials.

Fixes: e8a60aa7404b ("platform/x86: Introduce support for Systems Management Driver over WMI for Dell Systems")
Cc: stable@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Link: https://patch.msgid.link/20260303113050.58127-2-thorsten.blum@linux.dev
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>